Colony-forming capacity of CLL-1–defined CD34 subpopulations in normal bone marrow. CD34⁺CD38⁺CLL-1⁻ and CD34⁺CD38⁺CLL-1⁺ subpopulations were purified from NBM cells. Cell input was 2500 cells/mL for BFU-Es/CFU-GMs. Cell input for CFU-MKs was 5000 cells/mL. The number of colonies was determined after 14 days of culture. ■ shows the output of the CD34⁺CD38⁺CLL-1⁺ population; ▒, the CD34⁺CD38⁺CLL-1⁻ population. The error bars show the standard deviation. Two (CFU-MK) and 3 (burst-forming unit–erythroid [BFU-E]/CFU-GM) independent experiments were performed, each in duplicate.